Patients undergoing operations that require low blood flow or circulatory arrest often must have their body temperature lowered prior to surgery in order to help protect the heart and brain. In particular, hypothermia has been induced in patients undergoing cardiac surgery and operations for cerebral aneurysms. More recently, the lowering of body temperature has been used as a technique for protecting the brain in head trauma patients and there are indications that this procedure may be useful in treating patients for hemorrhagic shock. Unfortunately, there is, at present, no reliable noninvasive method for rapidly lowering a patient's body temperature. The present invention addresses this problem and discloses a method that can be used for rapidly inducing hypothermia or, alternatively, for rapidly warming a hypothermic patient.